JP2001097765A - Mullite crystal-containing ceramic and its manufacturing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a mullite crystal-containing ceramic, capable of inverting high strength to the ceramic, even when sewage sludge-incinerated ash is used as a raw material, and to provide a product composed of the same ceramic. SOLUTION: This method for manufacturing the subject ceramic from the sewage sludge-incinerated ash comprises (a) a process for charging the sewage sludge-incinerated ash, a clay mineral containing alumina in an amount of >=20 wt.% based on the total, and a ceramic material, (b) a process for mixing the ash, the clay mineral and the ceramic material, and (c) a process for baking the mixture formed by the mixing process, wherein a crystal quartz phase and an amorphous glass phase are formed in the ceramic to be contained mainly in a matrix of the ceramic, and a crystalline phase comprising mullite is formed in the amorphous glass phase. Thus, the ceramic which has the matrix mainly comprising the crystal quartz phase and the amorphous glass phase, and the amorphous glass phase of which contains the crystalline phase comprising mullite is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to ceramics and a technique for manufacturing the same. More specifically, the present invention relates to a method for producing high-strength ceramics from incinerated ash generated by incinerating sewage sludge and the like, and a high-strength ceramic product obtained by the method.

[0002]

2. Description of the Related Art When sewage sludge or the like is incinerated, a large amount of incinerated ash is generated as waste, so that effective utilization of such incinerated ash is desired. Conventionally, this kind of incinerated ash is used as it is as soil improvement material, etc., and the incinerated ash is once melted and converted into slag, then crushed to an appropriate size and reused as ceramic products such as concrete aggregates and roadbed materials. Have been. For example, JP-A-8-225
Japanese Patent Application Publication No. 363 and Japanese Patent Application Laid-Open No. 9-100151 describe ceramics using sewage sludge incineration ash and the like as a raw material and a method for producing the same.

[0003]

However, ceramics made from incinerated ash or the like manufactured by a conventional manufacturing method cannot achieve satisfactory strength. Therefore, ceramics made from such incinerated ash etc.
It could not be used as a ceramic pipe or other ceramic products requiring relatively high strength, and was only used for construction materials and civil engineering materials that do not require very high strength, such as tiles and tiles.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems relating to ceramics made from incinerated ash of sewage sludge or the like. An object of the present invention is to provide a method capable of obtaining a high-strength ceramic even using incinerated ash such as sewage sludge as a raw material, and a result thereof in order to further utilize incinerated ash such as sewage sludge. It is.

[0005]

In order to achieve the above object, the present invention relates to a method for producing ceramics from sewage sludge incineration ash or other sludge incineration ash, comprising the steps of (a). Supplying a sludge incineration ash and a clay material and a ceramic material having an alumina content of 20% by weight or more of the entire mineral substance, and (b). The sewage sludge incineration ash or other sludge incineration ash and a clay material And a step of mixing a ceramic material, and, (c) including a step of firing the mixture obtained by the mixing step, mainly producing a quartz crystal portion and an amorphous glass portion in the substrate, A method for producing a ceramic is provided, wherein a crystal part made of mullite is generated in the amorphous glass part.
In the present specification, the “ceramic material” refers to a ceramics-based inorganic material in a broad sense including cement, glass, brick, and the like. Crushed ceramics and cement powder are typical examples of the ceramic material referred to in this specification. In this specification, the term "clay material" refers to an inorganic material composed of various minerals (typically, various clay minerals and silicate minerals) that can constitute clay. The mineral portion of clay, such as kaolin, excluding the water content is a typical example of the clay material referred to in this specification.

In the method for producing a ceramic according to the present invention,
Supply and mix clay and ceramic materials to the incineration ash of sewage sludge or other sludge generated in large quantities as industrial waste. Thereby, even if the calcium component and the phosphoric acid component are present at a high rate in the sewage sludge incineration ash and the like, the content of these components can be relatively reduced in the mixture. Therefore, the denseness of the obtained fired product (ceramic sintered body) can be improved.

[0007] Further, the ceramic manufacturing method of the present invention is characterized in that as the clay material to be mixed (namely, the aggregate of minerals), a material having an alumina content of 20% by weight or more is used. As a result, the content of the alumina component is higher in the mixture than in the raw material incineration ash. Therefore, according to the ceramic manufacturing method of the present invention, a quartz crystal part (phase) and an amorphous glass part (phase) are generated as main constituents in a substrate (matrix) of the obtained fired product, and It is possible to segregate a crystal part composed of mullite which is a high-strength crystal in the amorphous glass. As a result, ceramics having higher strength than conventional ones (ie, ceramics derived from sewage sludge incineration ash) can be obtained.

In a preferred method of the present invention, in the step (b), the sewage sludge incineration ash or other sludge incineration ash is 20 to 40% by weight, the clay material is 30 to 40% by weight, Ceramic material 30 ~
These materials are mixed in a ratio of 40% by weight. By setting such a mixing ratio, it is possible to achieve both high density and high strength of the obtained ceramic.

In a further preferred method of the present invention, the P ₂ O ₅ content in the mixture mixed in the step (b) is 8% by weight or less of the whole mixture. Then, the sewage sludge incineration ash or other sludge incineration ash, the clay material, and the ceramic material are supplied and / or mixed. Alternatively, (b).
The incinerated ash, the clay material, and the ceramic material are supplied and / or mixed such that the CaO content in the mixture mixed in the step is 3% by weight or less of the entire mixture. By adjusting the raw materials to be mixed and the mixing ratio in this way, it is possible to obtain higher strength sewage sludge incineration ash or other ceramics derived from sludge incineration ash.

In another preferred method of the present invention for producing a ceramic material, in the step (a), the particle size of the clay material and the ceramic material is adjusted to 150 μm or less. Thereby, the miscibility of each raw material can be improved, and as a result, the denseness of the obtained fired product can be improved.

In another preferred method for producing a ceramic according to the present invention, the step (c) is carried out at 1050 to 1
The highest temperature is selected within the range of 200 ° C. Preferably, the heating is performed such that it takes at least 8 hours to raise the temperature from room temperature to the selected maximum temperature. By setting the conditions for the temperature increase, the efficiency of gas removal from the mixture during firing can be improved, and as a result, a highly dense sintered body can be obtained. Under particularly preferred temperature raising treatment conditions,
The temperature is raised from normal temperature to 500 ° C. at a rate of 125 ° C./hour or a slower rate.
By setting the heating rate, the organic components and / or the carbon components in the sludge incineration ash that can be added together with the clay material can be efficiently incinerated and removed.

Further, in order to achieve the above object, the present invention has a quartz crystal part and an amorphous glass part mainly in a substrate (that is, most of the substrate), and the amorphous glass part Provides various ceramic products (construction materials, civil engineering materials, etc.) substantially constituted by ceramics containing a crystal part composed of mullite. Thus, as a typical example of such a ceramic product, the present invention provides a ceramic tube (ceramic pipe) substantially constituted by the above ceramics. In the ceramic tube of the present invention, as a result of having the mullite crystal portion, high strength is realized. Therefore, it can be suitably used as a ceramic pipe for water and sewage requiring high strength.

A preferred ceramic tube of the present invention is a ceramic tube substantially constituted by ceramics obtained by the above-described method for producing ceramics of the present invention. The ceramic tube obtained based on such a manufacturing method has high strength as a result of having the mullite crystal part. Therefore, it is suitably used as a ceramic pipe for water and sewage requiring high strength. In addition, it can contribute to the effective reuse of sewage sludge incineration ash, which is industrial waste. A preferred porcelain tube of the present invention is one in which the mullite crystal portion accounts for 9% by weight or more of the above ceramics,
Particularly preferred is one in which the mullite crystal portion accounts for 15 to 17% by weight or more of the ceramics. A ceramic tube made of such a ceramic can have the same or a similar strength as a ceramic having a three-point bending strength of 80 MPa (1 Pa = 1.19772 × 10 ⁻⁵ kgf / cm ² ) or more. Such a high-strength porcelain tube can be suitably used as a porcelain tube for water supply and sewerage that requires particularly high strength, such as buried in soil.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for producing a ceramic according to the present invention will be described below.

First, regarding the above (a). Step (raw material supply step),
I will explain. In the ceramic manufacturing method of the present invention,
Means various sewage sludge incineration ash or other sludge incineration ash
Can be used without particular restrictions on composition. example
For example, incineration ash derived from general sewage sludge is
In general, it is composed of lime feldspar, phosphate compound, quartz, etc.
And SiO_TwoAs the main component and further Al_Two
O _Three, Na_TwoO, K_TwoO, MgO, Fe_TwoO_Three, P_TwoO_FiveEtc.
Contains, but does not affect these composition ratios,
Those containing trace components can also be used. In general,
Depending on the treatment method, sewage sludge incineration ash can be polymer-based and stone
Although it can be classified as ash-based,
it can. High molecular incineration ash can be used particularly preferably.

The clay material used in the method for producing ceramics of the present invention is not particularly limited as long as the alumina (Al ₂ O ₃ ) content is 20% by weight or more of the entire mineral substance. Those having low contents of CaO and P ₂ O _{5 which} cause vitreous formation at the time of firing are preferable for the practice of the present invention. As the composition ratio of such a clay material, for example, SiO ₂ : 57 to 67% by weight, Al ₂ O ₃ : 20 to
27 wt%, Fe ₂ O _3: less than 5 wt%, CaO: less than 1 wt%, MgO: less than 1 wt%, K ₂ O: less than 3 wt%, Na ₂ O: is preferable less than 1 wt%. on the other hand,
If Fe ₂ O ₃ , CaO, MgO, K ₂ O, and Na ₂ O are present in excess of the above composition ratio, the ratio of the glass phase in the obtained ceramic substrate becomes too high, and it is difficult to secure the desired strength. Become.

Further, as the above-mentioned clay material used in the method for producing ceramics of the present invention, a clay material having an alumina content of 25% by weight or more generates a large amount of a mullite crystal component (mullite phase). Particularly preferred. In particular, a clay material containing kaolinite as a main constituent clay mineral or a clay material having a low feldspar content is preferable. Such clay material is provided as such or as a source (natural or artificial preparation) containing the clay material. As a source containing such a clay material, a plastic natural clay is preferable, and a plurality of such natural clays may be mixed as necessary. Further, at the time of use, plastic clay containing moisture may be used, or dry clay which produces plasticity when water is added may be used. When clay is extruded, plastic clay is preferred.

The ceramic material in the method for producing ceramics of the present invention includes ceramic materials such as ceramics and porcelain, cement, glass, and crushed bricks. The ceramic material according to the present invention is preferably a material that acts to prevent gas from being accumulated in the low melting point amorphous glass that can be precipitated in the firing step. For example,
A crushed ceramic sintered body such as a tile chamotte or a ceramic pipe chamotte is suitable as a ceramic material. A ceramic material derived from a ceramic sintered body (crushed into a powder) obtained in a temperature range higher than the firing temperature in the ceramic manufacturing method of the present invention described below is particularly preferable. If the powder composed of the ceramic sintered body sintered at such a high temperature is used as the ceramic material according to the present invention, the sludge incineration ash and the clay are produced in the sintered body generated in the firing step in the ceramic manufacturing method of the present invention. Even when a low-melting amorphous glass derived from a material is generated, such a ceramic material remains as particles. As a result, pores for releasing gas generated in the low melting point amorphous glass to the outside can be secured. Furthermore, by adding such a ceramic material, the fire resistance performance of the mixture itself in the production method of the present invention can be improved.

Alternatively, a ceramic sintered body having excellent fire resistance made of crystalline SiO ₂ and / or mullite (typical composition formula: 3Al ₂ O ₃ .2SiO ₂ ) such as cristobalite, tridymite and quartz is pulverized. The powder obtained in this manner can also be used particularly preferably. The ceramic material made of such a powder can contribute to improving the strength of the incinerated ash-derived ceramic obtained by the production method of the present invention.

In the ceramic manufacturing method of the present invention, before mixing the sludge incineration ash, the clay material and the ceramic material, the clay material (or its supply source) and the ceramic material are preliminarily mixed so as to have a small particle size. It is preferable to perform a crushing process.
m or less. The sludge incineration ash used as a raw material is usually in the form of fine particles (fine powder), but the sludge incineration ash may be similarly subjected to a fine-granulation treatment.

For example, when various dry clays are used as the clay material, a powdery dry clay having a desired particle size can be obtained by fractionating through a sieve of about $ 100. When raw clay is used as a supply source containing a clay material, powdered raw clay having a desired particle size can be obtained by preliminarily dispersing in water and fractionating the mixture with a sieve. On the other hand, the ceramic material is pulverized by various pulverizers such as a roll crusher, an impact mill, a Raymond mill, and a vertical mill. Thus, the powdery ceramic material having a desired particle size can be obtained by drying and fractionating through a sieve of about $ 100.

Next, the step (b). (Raw material mixing step) will be described. As for each raw material prepared and supplied as described above, the sludge incineration ash (typically, sewage sludge incineration ash) is preferably 20 to 40% by weight, and the clay material is preferably 30 to 40% by weight.
% Of the ceramic material is mixed at a ratio of 30 to 40% by weight. When ceramics are produced based on this mixing ratio, it becomes easy to contain the mullite crystal portion in a ratio of 9% by weight or more of the obtained ceramics. On the other hand, if the mixing ratio of the above-mentioned sludge incineration ash is less than 20% by weight of the whole, it becomes difficult to obtain dense ceramics. On the other hand, when the mixing ratio of the sludge incineration ash is more than 40% by weight of the whole, there is a possibility that a large amount of the low melting point amorphous glass may be generated, and the strength may be insufficient. Also, the mixing ratio of the ceramic material is 4
If the content is more than 0% by weight, it becomes difficult to obtain a dense ceramic. On the other hand, if the mixing ratio of the ceramic material is less than 30% by weight of the whole, it is difficult to secure pores for discharging the gas to the outside. On the other hand, if the mixing ratio of the clay material is less than 30% by weight of the whole, the strength of the ceramic may be insufficient.

Alternatively, when mixing these three types of raw materials, the sludge incineration ash, the clay material, and the ceramic material are mixed such that the P ₂ O ₅ content in the mixture is 8% by weight or less of the whole mixture. Is preferably selected and / or mixed. Alternatively, it is preferable to select and / or mix the sludge incineration ash, the clay material, and the ceramic material such that the CaO content in the mixture is 3% by weight or less of the entire mixture. By reducing the P ₂ O ₅ content and the CaO content in the mixture in this way, it is possible to prevent the glass phase from being excessively generated, and to avoid insufficient strength of the ceramic.

The mixing means is not particularly limited, but is preferably a mixing means capable of obtaining a homogeneous mixture. A homogenous mixture composed of the above three kinds of raw materials can be obtained by a kneading means such as a pan mill such as a mix muller, a stirring mill such as a ball mill, a seed feeder, and a kneading machine. Particularly, a batch-type kneading device is suitable.

Next, the step (c) (the firing step) will be described. Typically, such a firing step involves, as a preliminary step, shaping the mixture into a desired shape. There is no particular limitation on such molding means,
Various methods conventionally used in the ceramic product manufacturing process can be used. For example, general cast molding, extrusion molding, press molding (uniaxial pressing, CIP
Molding method) can be employed to obtain a molded article composed of the above mixture. Of these, extrusion is particularly suitable for producing the above-mentioned ceramic tube of the present invention. In addition, when performing the casting molding, the extrusion molding, and the like, when the mixture is excessive in moisture, it is necessary to dry the mixture before the sintering process. In particular, it is desirable to carry out a drying treatment until the residual water content becomes 2% or less. This can eliminate the risk of steam expansion during the sintering reaction and explosion caused by the expansion. In addition, at the time of the mixing or molding, a suitable binder may be added to the mixture as needed.

The maximum firing temperature in the method for producing ceramics according to the present invention may vary depending on the mixing ratio of sludge incineration ash and the like, but is preferably 1000 to 1300 ° C.
And more preferably from 1,050 to 1,200 ° C.
Also, the holding time at the maximum temperature is typically about 1.5 hours or less. If the maximum firing temperature is significantly lower than the above temperature range, mullite crystal parts cannot be sufficiently generated. For this reason, a desired strength may not be secured. Conversely, even when the maximum firing temperature greatly exceeds the above-mentioned temperature range, mullite crystal parts cannot be sufficiently generated, and eventually the desired strength cannot be secured.

It is preferable to set the heating rate in the firing step so that the heating time from normal temperature to the maximum temperature requires at least 1.5 hours. If the temperature rises at an excessively fast pace, a dense glass phase may be rapidly formed on the surface layer of the sintered body. The formation of such a dense glass phase is not preferable because it promotes that the gas generated inside the sintered body is directly enclosed in the inside. This is because gas filling causes a reduction in strength. A slow heating rate such that the heating time is 8 hours or longer (for example, the heating time is 8 hours to 12 hours) is particularly preferable. According to such a slow heating rate, the efficiency of gas removal from the mixture during firing can be improved, and a highly dense ceramic having a water absorption of typically 1% or less can be obtained. More preferably, the temperature is set so that the temperature is raised from room temperature to 500 ° C. at a rate of 125 ° C./hour or a slower rate. By setting the heating rate, it is possible to efficiently incinerate and remove organic components that can be added together with the clay material in the mixture (that is, may be included in the supply source) and / or carbon components that can be included in the sludge incineration ash. it can.

The ceramics manufactured by the above-described method for manufacturing a ceramics of the present invention may have an amorphous glass part and a quartz crystal part as main constituents of the substrate, although it may vary depending on the composition of the raw materials used. In addition, the amorphous glass portion includes a mullite crystal portion (a mullite phase). Such mullite is typically columnar mullite segregated from a low melting point amorphous glass in a cooling process after sintering. Thus, a compressive stress field can be generated around the mullite crystals segregated in the glass due to a difference in thermal expansion coefficient, and as a result, high strength is realized. Preferably, the amorphous glass portion further includes a crystal portion made of hematite (Fe ₂ O ₃ ).
Thereby, the denseness can be improved. Further, it may include lime feldspar, soda feldspar and / or potassium feldspar in which a part of the low melting point amorphous glass part is crystallized.

According to the above-described ceramic manufacturing method of the present invention, various ceramic products can be manufactured from incinerated ash which is a residue obtained by incinerating sewage sludge which is industrial waste. In particular, since a high-strength product can be obtained by the present method, the manufactured ceramics can be applied to various uses. For example, products made of ceramics produced by the present method include interior or exterior building materials, civil engineering materials, and the like. For example, any ceramic product (for example, building materials such as tiles for interior and exterior,
Biomaterials such as artificial bones, and electronic materials such as ceramic substrates)
Can also be produced.

A typical example of a suitable ceramic product obtained by the present method is a ceramic pipe (ceramic pipe) used for water supply and sewerage. Hereinafter, the ceramic tube of the present invention will be described as a typical example of the ceramic product provided by the present invention.

The ceramic tube of the present invention has a quartz crystal portion and an amorphous glass portion in a substrate, and the amorphous glass portion is substantially constituted by ceramics containing a crystal portion made of mullite. This is a pottery tube characterized in that it has a structural characteristic. It is preferable that the crystal part composed of such mullite accounts for 9% by weight or more of the whole ceramics constituting the ceramic tube. In addition, as a pipe which is buried in the soil as a water pipe or a sewer pipe, a ceramic pipe substantially composed of ceramics having a three-point bending strength of 80 MPa or more or ceramics having a strength equivalent thereto is preferable. The ceramic tube of the present invention having these performances has the same composition as the above-described ceramic manufacturing method of the present invention, or a method according to the present method, for example, the case where the above three kinds of raw materials are mixed in place of sludge incineration ash or the like. This is a production method characterized by using a high-purity artificial raw material prepared in advance, and can be produced by a production method capable of obtaining a result equivalent to the ceramic production method of the present invention.

When the ceramic tube of the present invention is manufactured by the ceramic manufacturing method of the present invention, the above-mentioned (a).
(b) The raw material mixing step and (c).
There is no particular limitation. Typically, an extruder (eg, an auger type) having a die having a certain size and shape is extruded from the die while supplying the mixture (or a binder or the like) to the extruder to form an integral cross-sectional shape. A tubular molded article having the same can be obtained. Thus, such a tubular molded body is appropriately dried, as described above, and then fired under the above-described temperature conditions according to the present invention, whereby a ceramic tube of the present invention having a desired shape can be obtained. . The extrusion technique itself and the mechanism and operation method of the extruder used for the extrusion are well known in the art and do not particularly characterize the present invention, and therefore, detailed description thereof is omitted. I do.

[0033]

The present invention will be described in more detail with reference to the following examples, but it is not intended to limit the present invention to those shown in the examples.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

Using the sewage sludge incineration ash, clay material (here, dry clay powder for sculpture) and the above ceramic material (here, ceramic pipe chamotte) having the composition shown in Table 1, the ceramic production method of the present invention was carried out. Nine types of ceramics having different compositions were produced. That is, in Table 2, No. 1 to N
o. The above three kinds of raw materials were mixed at a total of nine mixing ratios (weight% in terms of dry powder) shown as 9. Table 3 shows the composition ratio of minerals present in each of the mixtures (No. 1 to No. 9) calculated based on this mixture ratio. Thus, for mixing these raw materials, an Ishikawa-type mixer was used. Next, each mixture was preformed by a uniaxial press, and then 1500
CIP molding was performed under a pressure (hydrostatic pressure) of ton / cm ² . This was fired for one hour at the firing temperature shown in Table 2 according to the amount of sewage sludge incineration ash added. The heating rate from room temperature to each firing temperature is 1 hour / hour from room temperature to 500 ° C.
The temperature was set to 125 ° C./hour from 00 ° C. and 500 ° C. to each firing temperature.

After completion of the firing step, the obtained ceramic was cut into a 3 × 4 × 40 L bending strength test piece and subjected to a conventional method (JI
A three-point bending test was performed based on SR 1601). In addition, the water absorption was evaluated. After the bending strength test, each test piece was pulverized and subjected to powder X-ray diffraction analysis. Table 4 shows the results. In addition, No. in Table 4 1 to No. 9
Is the No. of the above mixture. It corresponds to. The test piece N
o. 1 shows the result of powder X-ray diffraction (XRD pattern) of FIG.
The test piece No. 2-No. 8 shows the result of the powder X-ray diffraction (XRD pattern) of FIG.

[0039]

[Table 4]

As is clear from Table 4 and FIGS. 1 and 2, N having a three-point bending strength exceeding 90 MPa was recognized.
o. 1 to No. All of the test pieces (ceramics) of No. 5 contained quartz (black circles in the figure), mullite (white circles in the figure), hematite (black triangles in the figure), and neferrite (white triangles in the figure) as crystal phases. Was observed. These test pieces also had a low water absorption of 0.2 to 0.3%, suggesting that they had a very dense structure. On the other hand, the three-point bending strength is 80 to
No. 90 MPa. 6-No. In the test piece (ceramics) of No. 8, it was recognized that anorthite (open square in the figure) was further present as a crystal phase. These test pieces had a water absorption of 0.5 to 0.7%. In addition, the mixing ratio of the sewage sludge incineration ash was 50% by weight of the whole, and the mixing ratio of the clay material and the ceramic material was 25% by weight of the whole, respectively. In the test piece of No. 9, the three-point bending strength was less than 80 MPa. According to the mixing ratio, the abundance ratios of CaO and P ₂ O ₅ exceeded 3% by weight and 8% by weight, respectively. The water absorption was 1.5%.

Next, the above No. The microstructure of the ceramic obtained under the same conditions as in Example 1 was examined with an electron microscope (TEM: × 400
00). FIGS. 3 and 4 show the obtained TEM photographs. As is clear from these electron micrographs,
The substrate of the ceramics of the present invention obtained in this example is a portion mainly composed of quartz crystal (portion indicated by A in FIG. 3).
And amorphous glass (Si-Al-P-Ca-KO system)
(A portion indicated by B in FIG. 3). The amorphous glass portion includes a crystal portion made of mullite (a portion shown by C in FIG. 4) and a crystal portion made of hematite (a portion indicated by C in FIG. 4). 4 (a portion indicated by D in FIG. 4). Specifically, mullite was 17% by weight, hematite was 9% by weight, quartz was 68% by weight, and neferrite was 6% by weight.

[0042]

According to the method for producing ceramics of the present invention, high-strength ceramics can be produced even using sewage sludge incineration ash as a raw material. Further, by such a manufacturing method, a ceramic pipe or other ceramic products having high strength can be manufactured from incinerated sewage sludge as industrial waste. Therefore, according to the present invention, further effective utilization of sewage sludge incineration ash, which is industrial waste, can be achieved.

[Brief description of the drawings]

FIG. 1 shows a powder X of a ceramic of the present invention according to one embodiment.
It is a graph which shows a line diffraction pattern (XRD pattern).

FIG. 2 shows a powder X of the ceramic of the present invention according to one embodiment.
It is a graph which shows a line diffraction pattern (XRD pattern).

FIG. 3 is an electron micrograph (TEM photograph) showing the fine structure of the ceramic of the present invention according to one example.

FIG. 4 is an electron micrograph (TEM photograph) showing the fine structure of the ceramic of the present invention according to one example.

Continuation of the front page (72) Inventor Misao Iwata 3-36 Noritake Shinmachi, Nishi-ku, Nagoya-shi, Aichi F-term (reference) in Noritake Co., Ltd. 4D059 AA03 BB01 CC04 4G030 AA27 AA36 AA37 BA20 CA01 HA05

Claims (4)

[Claims] 1. A method for producing ceramics from sewage sludge incineration ash, comprising: (a) a sewage sludge incineration ash, a clay material having an alumina content of 20% by weight or more of the entire mineral substance, and a ceramic. (B) mixing the sewage sludge incineration ash, clay material, and ceramic material; and (c) firing the mixture obtained by the mixing process. A method for producing a ceramic, wherein a quartz crystal part and an amorphous glass part are mainly produced in a substrate, and a crystal part composed of mullite is produced in the amorphous glass part. 2. In the step (b), the sewage sludge incineration ash is 20 to 40% by weight, the clay material is 30 to 40% by weight, and the ceramic material is 30 to 40% by weight. The ceramic manufacturing method according to claim 1, wherein the ceramics are mixed. 3. A ceramic tube having a quartz crystal part and an amorphous glass part mainly in a substrate, wherein the amorphous glass part is substantially constituted by ceramics containing a crystal part made of mullite. 4. A ceramic produced by the method for producing a ceramic according to claim 1 or 2, wherein the substrate mainly has a quartz crystal part and an amorphous glass part, and the amorphous glass part has A ceramic tube substantially composed of ceramics containing a crystal part composed of mullite.